Should i fix the TBI or go to carb? And what's this wire?

[AyWoSch Motors]

tbimods has some decent info, for sure. especially if you are looking to make mods and more power. but nothing beats the Drive-ability manual from GM if you are messing with a stock system. it is like the Bible on TBI and is available in the reference library on this site.

The driveablitlity manual was helpful. I rediagnosed with that and its telling me wiring or ECM.
Not fixing the wiring and im buying a nothing computer, so there we go, lol

 

[AuroraGirl]

Thanks. I just checked it out.
Looked threw a bit, looked at the troubleshooting section. All je said on there about what i got going on is "check your grounds".

DID YOU?

 

[AuroraGirl]

You must be registered for see images attach

 

[Ricko1966]

I still want to know why he doesn't have his constant 12v source.

 

[AuroraGirl]

I still want to know why he doesn't have his constant 12v source.

bad fuse box connection, or wire, or fuse blown, or not grounded etc maybe

 

[Ricko1966]

bad fuse box connection, or wire, or fuse blown, or not grounded etc maybe

Read post 20 and 26

 

[AuroraGirl]

Read post 20 and 26

Oh THAT always hot. There should be 2 potential ground sources for it, but always hot sounds proper to me since it eliminates a potential failure point when the ground can be the only switching going on.

 

[AyWoSch Motors]

DID YOU?

Yes, i did. All are fine

 

[AyWoSch Motors]

bad fuse box connection, or wire, or fuse blown, or not grounded etc maybe

Checked both ecm fuses, they're fine.

 

[Ricko1966]

2 hots at the fp relay? 1hot at each injector when unplugged.hot to the ecm?

 

[Ricko1966]

Do you have pulse at the injectors?

 

[gmbellew]

The driveablitlity manual was helpful. I rediagnosed with that and its telling me wiring or ECM.
Not fixing the wiring and im buying a nothing computer, so there we go, lol

computers are available and pretty straightforward to swap out. you can likely use your current PROM chip.

did you go through the crank, no start chart?

what circuit did it say had wiring issues?

 

[AyWoSch Motors]

computers are available and pretty straightforward to swap out. you can likely use your current PROM chip.

did you go through the crank, no start chart?

what circuit did it say had wiring issues?

I went threw the flow chart with the knowledge i had gained when working on it a few months ago. Got to a certain point and i had to go check more things. So i hooked a battery to it to re-check some things, and now everything has changed. So i went threw it again and now it telling me all sorts of other things are bad, that i know aren't because i replaced them.
Im going crazy chasing my tail with this thing. Everytime i mess with, something else stops working.

When i was trying to fix it for my boss it ran great then it didnt.
Power the pump, but pump wouldn't come on, so i replaced it. Ran for a few minutes, then died. Then i wasnt getting power to the pump anymore, so i changed the relay. Relay was then clicking like it should, but no pump. So i pulled the pump, it was working, when I'd jump the wires, but seemed like power wasn't going threw the sending unit, so we got a whole new sender unit and new pump. Now relay was clicking pump was coming on, getting fuel to the TBI, but no fuel coming out. So i went threw all that, new regulator, new pressure sensor, new used injectors, new gaskets, still no fuel. Checked the injector pulse, no pulse. Checked the injector wiring, all the connectors, wiring around everything, cleaned and tightened the ground on the thermostat, checked all the ground straps, checked the fuses, still nothing.
Now fast forward a few months, i now own it. I expect to put a battery in it and have it be exactly like it was... no..
Now i still dont have injector pulse, but now the relay doest come on, theres power to it, but not consistant, it changes. I wast getting power to the pump, then i was, then i wasn't, but it wouldnt come on at all. Checked the pump, its now dead, wont work at all. Changed pump to another one i had, no power. Jump the test port, still not working.
Bypassed all that, put in a 12volt external pump my buddy loaned me, hot wired directly off a battery, bypassing the truck entirely. Now i have fuel to the TBI again going up and coming back. Still no injector pulse, still wont run. Same thing as before, but now more things don't work

Im very very agrivated. Feels like im chasing my tail going in circles, fixing and bypassng, just to end up at the same place. Ready to burn it to the ground. Wish it had a carburetor ad mechanical pump.
Im so done with trying to fix this stupid POS.

Im very agrivated, can you tell?

 

[gmbellew]

I went threw the flow chart with the knowledge i had gained when working on it a few months ago. Got to a certain point and i had to go check more things. So i hooked a battery to it to re-check some things, and now everything has changed. So i went threw it again and now it telling me all sorts of other things are bad, that i know aren't because i replaced them.
Im going crazy chasing my tail with this thing. Everytime i mess with, something else stops working.

When i was trying to fix it for my boss it ran great then it didnt.
Power the pump, but pump wouldn't come on, so i replaced it. Ran for a few minutes, then died. Then i wasnt getting power to the pump anymore, so i changed the relay. Relay was then clicking like it should, but no pump. So i pulled the pump, it was working, when I'd jump the wires, but seemed like power wasn't going threw the sending unit, so we got a whole new sender unit and new pump. Now relay was clicking pump was coming on, getting fuel to the TBI, but no fuel coming out. So i went threw all that, new regulator, new pressure sensor, new used injectors, new gaskets, still no fuel. Checked the injector pulse, no pulse. Checked the injector wiring, all the connectors, wiring around everything, cleaned and tightened the ground on the thermostat, checked all the ground straps, checked the fuses, still nothing.
Now fast forward a few months, i now own it. I expect to put a battery in it and have it be exactly like it was... no..
Now i still dont have injector pulse, but now the relay doest come on, theres power to it, but not consistant, it changes. I wast getting power to the pump, then i was, then i wasn't, but it wouldnt come on at all. Checked the pump, its now dead, wont work at all. Changed pump to another one i had, no power. Jump the test port, still not working.
Bypassed all that, put in a 12volt external pump my buddy loaned me, hot wired directly off a battery, bypassing the truck entirely. Now i have fuel to the TBI again going up and coming back. Still no injector pulse, still wont run. Same thing as before, but now more things don't work

Im very very agrivated. Feels like im chasing my tail going in circles, fixing and bypassng, just to end up at the same place. Ready to burn it to the ground. Wish it had a carburetor ad mechanical pump.
Im so done with trying to fix this stupid POS.

Im very agrivated, can you tell?

i feel your pain. man. electrical issues can be frustrating. sounds like it is worth swapping the ECM to check. worst case you will have a spare and your out $150. but I'd be looking at the main wiring harness running across the firewall for issues (rub through that is shorting, etc) with the 440 circuit (orange wire) that goes to oil pressure switch, fuel pump relay, and powers the ECM. likely spots for rub through are the cruise control bracket and MAP sensor bracket. another potential issue i have seen folks have is bad/loose connections at the Ignition Control Module and/or coil. I remember a member here swapped his TBI to carb because of a similar issue. then found a loose pin on the module connector that was likely his issue the whole time. not sure if he ever got his carb set up going, I remember he had issues with that as well.

 

[AuroraGirl]

I went threw the flow chart with the knowledge i had gained when working on it a few months ago. Got to a certain point and i had to go check more things. So i hooked a battery to it to re-check some things, and now everything has changed. So i went threw it again and now it telling me all sorts of other things are bad, that i know aren't because i replaced them.
Im going crazy chasing my tail with this thing. Everytime i mess with, something else stops working.

When i was trying to fix it for my boss it ran great then it didnt.
Power the pump, but pump wouldn't come on, so i replaced it. Ran for a few minutes, then died. Then i wasnt getting power to the pump anymore, so i changed the relay. Relay was then clicking like it should, but no pump. So i pulled the pump, it was working, when I'd jump the wires, but seemed like power wasn't going threw the sending unit, so we got a whole new sender unit and new pump. Now relay was clicking pump was coming on, getting fuel to the TBI, but no fuel coming out. So i went threw all that, new regulator, new pressure sensor, new used injectors, new gaskets, still no fuel. Checked the injector pulse, no pulse. Checked the injector wiring, all the connectors, wiring around everything, cleaned and tightened the ground on the thermostat, checked all the ground straps, checked the fuses, still nothing.
Now fast forward a few months, i now own it. I expect to put a battery in it and have it be exactly like it was... no..
Now i still dont have injector pulse, but now the relay doest come on, theres power to it, but not consistant, it changes. I wast getting power to the pump, then i was, then i wasn't, but it wouldnt come on at all. Checked the pump, its now dead, wont work at all. Changed pump to another one i had, no power. Jump the test port, still not working.
Bypassed all that, put in a 12volt external pump my buddy loaned me, hot wired directly off a battery, bypassing the truck entirely. Now i have fuel to the TBI again going up and coming back. Still no injector pulse, still wont run. Same thing as before, but now more things don't work

Im very very agrivated. Feels like im chasing my tail going in circles, fixing and bypassng, just to end up at the same place. Ready to burn it to the ground. Wish it had a carburetor ad mechanical pump.
Im so done with trying to fix this stupid POS.

Im very agrivated, can you tell?

your vehicle, your choices, but truly speaking if you were back in the early stages of enthusiast / working on your own stuff, and had to learn TBI or Carb stuff from a neutral stand point, you would very much like TBI. I understand your frustrations, and without seeing the condition of any of this underhood stuff, I cant sa ywhat I would do. but if I had wiring worse than my f150 , out of shear avoiding ghost/random issues and cut out the "rot" I would cut it out and go old school. But if I had a solid foundation and just needed some checks with step-by-step validation etc I would keep the TBI and troubleshoot.